RFC 3670 (rfc3670) - Page 2 of 97
Information Model for Describing Network Device QoS Datapath Mechanisms
Alternative Format: Original Text Document
RFC 3670 QoS Device Datapath Info Model January 2004
This document, as well as QPIM, are information models. That is,
they represent information independent of a binding to a specific
type of repository.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Policy Management Conceptual Model . . . . . . . . . . . 6
1.2. Purpose and Relation to Other Policy Work. . . . . . . . 7
1.3. Typical Examples of Policy Usage . . . . . . . . . . . . 7
2. Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2.1. Common Needs Of DiffServ and IntServ . . . . . . . . . . 8
2.2. Specific Needs Of DiffServ . . . . . . . . . . . . . . . 9
2.3. Specific Needs Of IntServ. . . . . . . . . . . . . . . . 9
3. Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.1. Level of Abstraction for Expressing QoS Policies . . . . 10
3.2. Specifying Policy Parameters . . . . . . . . . . . . . . 11
3.3. Specifying Policy Services . . . . . . . . . . . . . . . 12
3.4. Level of Abstraction for Defining QoS Attributes and
Classes. . . . . . . . . . . . . . . . . . . . . . . . . 13
3.5. Characterization of QoS Properties . . . . . . . . . . . 14
3.6. QoS Information Model Derivation . . . . . . . . . . . . 15
3.7. Attribute Representation . . . . . . . . . . . . . . . . 16
3.8. Mental Model . . . . . . . . . . . . . . . . . . . . . . 17
3.8.1. The QoSService Class . . . . . . . . . . . . . . 17
3.8.2. The ConditioningService Class. . . . . . . . . . 18
3.8.3. Preserving QoS Information from Ingress to
Egress . . . . . . . . . . . . . . . . . . . . . 19
3.9. Classifiers, FilterLists, and Filter Entries . . . . . . 21
3.10. Modeling of Droppers . . . . . . . . . . . . . . . . . . 23
3.10.1. Configuring Head and Tail Droppers . . . . . . . 23
3.10.2. Configuring RED Droppers . . . . . . . . . . . . 24
3.11. Modeling of Queues and Schedulers. . . . . . . . . . . . 25
3.11.1. Simple Hierarchical Scheduler. . . . . . . . . . 25
3.11.2. Complex Hierarchical Scheduler . . . . . . . . . 27
3.11.3. Excess Capacity Scheduler. . . . . . . . . . . . 29
3.11.4. Hierarchical CBQ Scheduler . . . . . . . . . . . 31
4. The Class Hierarchy. . . . . . . . . . . . . . . . . . . . . . 33
4.1. Associations and Aggregations. . . . . . . . . . . . . . 33
4.2. The Structure of the Class Hierarchies . . . . . . . . . 34
4.3. Class Definitions. . . . . . . . . . . . . . . . . . . . 38
4.3.1. The Abstract Class ManagedElement. . . . . . . . 38
4.3.2. The Abstract Class ManagedSystemElement. . . . . 39
4.3.3. The Abstract Class LogicalElement. . . . . . . . 39
4.3.4. The Abstract Class Service . . . . . . . . . . . 39
4.3.5. The Class ConditioningService. . . . . . . . . . 39
4.3.6. The Class ClassifierService. . . . . . . . . . . 40
4.3.7. The Class ClassifierElement. . . . . . . . . . . 41
Moore, et al. Standards Track